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United States Patent |
5,686,810
|
Yasui
|
November 11, 1997
|
Charging device
Abstract
In the charging device, when the secondary battery is charged, charging
electrodes are electrically connected to the battery electrodes. When
charging of the battery is completed, charging operation of the charging
device is completed, and the charging electrodes are moved away from the
battery electrodes so that the charging electrodes are disconnected from
the battery electrodes.
Inventors:
|
Yasui; Tsuneo (Nagoya, JP)
|
Assignee:
|
Brother Kogyo Kabushiki Kaisha (Aichi-Ken, JP)
|
Appl. No.:
|
704848 |
Filed:
|
August 28, 1996 |
Foreign Application Priority Data
Current U.S. Class: |
320/113; 320/107; 320/162; 429/97 |
Intern'l Class: |
H01M 010/46 |
Field of Search: |
320/2,5
D13/103,107
429/97,98
|
References Cited
U.S. Patent Documents
5159256 | Oct., 1992 | Mattinger et al. | 320/2.
|
5530334 | Jun., 1996 | Ramspeck et al. | 320/2.
|
5594314 | Jan., 1997 | Hagiuda et al. | 320/2.
|
Primary Examiner: Tso; Edward
Attorney, Agent or Firm: Kane, Dalsimer, Sullivan, Kurucz, Levy, Eisele and Richard, LLP
Claims
What is claimed is:
1. A charging device for charging a secondary battery, said charging device
having a plurality of charging electrodes for supplying electrical
current, said secondary battery having a plurality of battery electrodes
through which said electrical current is supplied from said plurality of
charging electrodes, said device comprising:
a charging completion detector for detecting whether charging of said
secondary battery is completed;
a mechanism for insulating connection between said plurality of charging
electrodes with said plurality of battery electrodes when said charging
completion detector detects that the charging of said secondary battery is
completed.
2. The charging device according to claim 1, wherein said mechanism
disconnects said plurality of charging electrodes with said plurality of
battery electrodes by relatively moving said plurality of charging
electrodes away from said plurality of battery electrodes.
3. The charging device according to claim 2, wherein said charging
electrodes can be positioned at a first position where said charging
electrodes contact said plurality of battery electrodes respectively, and
a second position where said charging electrodes do not contact said
plurality of battery electrodes, and wherein said mechanism positions said
charging electrodes at said first position or said second position in
accordance with the detection result of said charging completion detector.
4. The charging device according to claim 3, wherein said mechanism
comprises an arm member on which said plurality of charging electrodes are
mounted, and a driving mechanism for driving said arm member.
5. The charging device according to claim 4, wherein said arm member is
rotatably supported about an axis, a gear portion be formed on said arm
member abut said axis, wherein said mechanism comprises a gear member
connected to a motor, said gear member being engaged with said gear
portion formed on said arm member, and wherein said arm member is moved
between said first and second positions as said motor rotates said gear
member.
6. The charging device according to claim 2, wherein said mechanism
comprises a biasing member for biasing said plurality of charging
electrodes in a direction where said plurality of charging electrodes
contact said plurality of battery electrodes, respectively, and an
actuator for moving said plurality of charging electrodes away from said
plurality of battery electrodes against a biasing force of said biasing
member.
7. The charging device according to claim 6, wherein said actuator
comprises a solenoid having a coil and a movable member, said movable
member being moved when said coil is energized, and wherein said movable
member is capable of moving said plurality of charging electrodes.
8. The charging device according to claim 1, wherein said detector
comprises a voltage detector for detecting a voltage of said secondary
battery, and wherein said detector determines that the charging of said
secondary battery is completed when said voltage of said secondary battery
becomes within a predetermined voltage range.
9. A charging device for charging a secondary battery, said charging device
having a plurality of charging electrodes for supplying electrical
current, said secondary battery having a plurality of battery electrodes
through which said electrical current is supplied from said plurality of
charging electrodes, said device comprising:
a first mechanism for allowing said plurality of charging electrodes to
contact said plurality of battery electrodes, said first mechanism being
neutrally effected;
a second mechanism for insulating said plurality of charging electrodes
from said plurality of battery electrodes; and
a controller for activating said second mechanism when charging of said
second battery is not being executed.
10. The charging device according to claim 9, wherein said controller
activates said second mechanism only when said charging is once started
and then terminated.
11. The charging device according to claim 9, further comprising a detector
for detecting whether charging of said secondary battery is completed
while said charging is executed, and wherein said controller activates
said second mechanism if said detector detects that said charging of said
secondary battery is completed.
12. The charging device according to claim 11, further comprising a current
source, controlled by said controller, for supplying electrical current to
said plurality of charging electrodes, and wherein said controller
controls said current source to supply said electrical current when said
charging is executed, and to stop supplying said electrical current when
said detector detects that said charging is completed.
13. The charging device according to claim 9, further comprising a battery
receiving portion on which said secondary battery is mounted, said
plurality of battery electrodes being provided on a surface facing said
battery receiving portion, said plurality of charging electrodes being
arranged at said battery receiving portion on a battery receiving surface
facing said secondary battery.
14. The charging device according to claim 13, wherein said battery
receiving surface being provided with a plurality of openings through
which said plurality of charging electrodes protrude, respectively, and
wherein said first mechanism comprises an electrodes supporting member on
which said plurality of charging electrodes are planted, said electrodes
supporting member being movable between at least first position where said
plurality of charging electrodes are press-contacted with said plurality
of battery electrodes, respectively, and a second position where said
plurality of charging electrodes are retracted from said battery receiving
surface and do not contact said plurality of battery electrodes.
15. The charging device according to claim 14, wherein said first mechanism
further comprises a biasing member for biasing said electrodes supporting
member to be positioned at said first position.
16. The charging device according to claim 15, wherein said second
mechanism further comprises an actuator for moving said electrodes
supporting member to be positioned at said second position against a
biasing force of said biasing member.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a charging device for charging a secondary
battery such as a Nickel-Cadmium battery.
Conventionally, there is known a charging device for charging a chargeable
battery such as a Nickel-Cadmium battery and the like. An example of such
a charging device is shown in FIG. 1. FIG. 1 is a perspective view of a
secondary battery (i.e., a chargeable battery) 60 and a conventional
battery charging device 58 for charging the secondary battery 60. The
charging device 58 has a battery accommodating chamber 62 on the upper
portion of the body thereof. The battery 60 is fitted in the accommodation
chamber 62 and mounted on the battery charging device 58. On the bottom
surface of the battery 60, as shown in FIG. 1, a plurality of electrodes
63 are provided. Corresponding to the electrodes 63 of the battery, a
plurality of charging electrodes 64 are provided on the bottom surface 62a
of the accommodating chamber 62. The charging electrodes 64 are projected
through openings 61 formed on the bottom surface 62a, and biased upwardly
so that the charging electrodes 64 keep contacting the battery electrodes
63 when the battery 60 is mounted on the charging device 58.
Generally, when charging is completed, the temperature of the secondary
battery 60 increases extremely. In the charging device as described above,
with use of a temperature detector such as a thermostat, the temperature
of the battery 60 is detected, and if the temperature increases extremely,
charging is stopped in order to avoid deterioration of the battery 60 due
to an overcharging.
In the conventional battery charging device, however, even if the charging
operation is stopped when the charging of the battery is completed, the
battery electrodes and the charging electrodes are maintained to contact.
If the battery is not removed from the charging device, discharging may
occur through the battery electrodes and the charging electrodes. Further,
corrosion of the battery electrodes and the charging electrodes may occur
since they keep contacting after the battery has been charged.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved
charging device which does not deteriorate a battery even if the battery
stays mounted on the charging device.
For the above object, according to an aspect of the invention, there is
provided a charging device a charging device for charging a secondary
battery, the charging device having a plurality of charging electrodes for
supplying electrical current, the secondary battery having a plurality of
battery electrodes through which the electrical current is supplied from
the plurality of charging electrodes, the device comprising:
a charging completion detector for detecting whether charging of the
secondary battery is completed;
a mechanism for insulating connection between the plurality of charging
electrodes with the plurality of battery electrodes when the charging
completion detector detects that the charging of the secondary battery is
completed.
Optionally, the mechanism is capable of disconnecting the plurality of
charging electrodes with the plurality of battery electrodes by relatively
moving the plurality of charging electrodes away from the plurality of
battery electrodes.
Further, the charging electrodes can be positioned at a first position
where the charging electrodes contact the plurality of battery electrodes
respectively, and a second position where the charging electrodes do not
contact the plurality of battery electrodes. The mechanism positions the
charging electrodes at the first position or the second position in
accordance with the detection result of the charging completion detector.
Optionally, the mechanism has an arm member on which the plurality of
charging electrodes are mounted, and a driving mechanism for driving the
arm member to move the charging electrodes.
Further, the arm member may be rotatably supported about an axis, and the
arm member has a gear portion which is formed about the axis. Furthermore,
the mechanism has a gear member which is connected to a motor. The gear
member is engaged with the gear portion of the arm member. The arm member
is moved between the first and second positions as the motor rotates the
gear member.
The mechanism may have a biasing member for biasing the plurality of
charging electrodes in a direction where the plurality of charging
electrodes contact the plurality of battery electrodes, respectively, and
an actuator for moving the plurality of charging electrodes away from the
plurality of battery electrodes against a biasing force of the biasing
member.
Further optionally, the actuator may be composed of a solenoid having a
coil and a movable core, the plurality of charging electrodes being moved
by the movable core when the solenoid is energized.
Still optionally, the detector may include a voltage detector for detecting
a voltage of the secondary battery. The detector nay determine that the
charging of the secondary battery is completed when the voltage of the
secondary battery becomes within a predetermined voltage range.
According to another aspect of the invention, there is provided a charging
device for charging a secondary battery, the charging device having a
plurality of charging electrodes for supplying electrical current, the
secondary battery having a plurality of battery electrodes through which
the electrical current is supplied from the plurality of charging
electrodes, the device comprising:
a first mechanism for allowing the plurality of charging electrodes to
contact the plurality of battery electrodes, the first mechanism being
neutrally effected;
a second mechanism for insulating the plurality of charging electrodes from
the plurality of battery electrodes; and
a controller for activating the second mechanism when charging of the
second battery is not being executed.
Optionally, the controller activates the second mechanism only when the
charging is once started and then terminated.
Further, the charging device may include a detector for detecting whether
charging of the secondary battery is completed while the charging is
executed. The controller activates the second mechanism if the detector
detects that the charging of the secondary battery is completed.
Furthermore, the charging device is provided with a current source,
controlled by the controller, for supplying electrical current to the
plurality of charging electrodes. The controller controls the current
source to supply the electrical current when the charging is executed, and
to stop supplying the electrical current when the detector detects that
the charging is completed.
Further optionally, the charging device may have a battery receiving
portion on which the secondary battery is mounted, the plurality of
battery electrodes being provided on a surface facing the battery
receiving portion, the plurality of charging electrodes being arranged at
the battery receiving portion on a battery receiving surface facing the
secondary battery.
Further, a plurality of openings are formed on the battery receiving
surface, and the plurality of charging electrodes protrude provided
through the plurality of openings, respectively. The first mechanism
comprises an electrodes supporting member on which the plurality of
charging electrodes are planted, the electrodes supporting member being
movable between at least first position where the plurality of charging
electrodes are press-contacted with the plurality of battery electrodes,
respectively, and a second position where the plurality of charging
electrodes are retracted from the battery receiving surface and do not
contact the plurality of battery electrodes.
Furthermore, the first mechanism further comprises a biasing member for
biasing the electrodes supporting member to be positioned at the first
position.
Still further, the second mechanism further comprises an actuator for
moving the electrodes supporting member to be positioned at the second
position against a biasing force of the biasing member.
DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIG. 1 is a perspective view showing a conventional secondary battery and a
conventional charging device therefor;
FIG. 2 a perspective view showing a secondary battery and a charging device
embodying the present invention;
FIG. 3 is a III--III cross sectional view of the charging device shown in
FIG. 2;
FIG. 4 is a cross sectional view of the charging device on which the
secondary battery is mounted, when charging electrodes contact the battery
electrodes;
FIG. 5 is a cross sectional view of the charging device similar to FIG. 4
except that the charging electrodes are disconnected from the battery
electrodes;
FIG. 6 is a block diagram showing a control system of the charging device;
FIG. 7 is a flowchart illustrating an operation executed by a control unit
of the charging device;
FIG. 8 is a cross sectional view of a second embodiment of the charging
device with the secondary battery is mounted, when charging electrodes
contact the battery electrodes;
FIG. 9 is a cross sectional view of the charging electrode; and
FIG. 10 is a cross sectional view of the charging device similar to FIG. 8
except that the charging electrodes are disconnected from the battery
electrodes.
DESCRIPTION OF THE EMBODIMENT
FIG. 2 is a perspective view of a charging device 10 embodying the
invention, and a chargeable battery 12. FIG. 3 is a cross sectional view
of the charging device 12 seen from a line III--III of FIG. 2.
As shown in FIG. 2, the charging device 10 has a casing 11. A front surface
of the casing 11 is formed to be a stepped surface where a display panel
15 for indicating charging condition of the battery is provided. Inside
the casing 11, as shown in FIG. 2, a current source unit 16 for supplying
electrical current to the battery 12, and a control unit 17 for
controlling the entire operation of the charging device 10 are provided.
On the top portion of the charging device 10, a stepped receptacle 14 is
formed for receiving and holding the bottom portion of the battery 12 when
the battery 12 is mounted on the charging device 10 to be charged. On side
surfaces 14a and 14a', which face to each other, lock pins 18a and 18a'
are projected. The lock pins 18a and 18a' are respectively biased in the
direction where they project from the side surfaces 14a and 14a' by
compression coil springs 19a and 19a' as shown in FIG. 3. On the side
surfaces of the battery 12, corresponding to the lock pins 18a and 18a',
engaging stepped portions 12a and 12a' are formed as shown in FIG. 2. When
the battery 12 is mounted on the charging device 10, the lock pins 18a and
18a' are once moved by the side surfaces of the battery 12 in the
direction opposite to the biased direction, respectively, and then the
lock pins 18a and 18a' engage with the stepped portions 12a and 12a' when
the battery 12 is completely mounted on the charging device 10, i.e., when
the battery 12 is held at the receptacle 14.
On the bottom surface 12b of the battery 12, two battery electrodes 13a and
13b are provided. Corresponding to the battery electrodes 13a and 13b,
from the bottom surface 14b of the receptacle 14, charging electrodes 24a
and 24b are projected through openings 14c and 14c' which are formed on
the bottom surface 14b.
Further, on the bottom surface 14b, a temperature sensor 30 for detecting
the temperature of the battery 12 is provided. Next to the temperature
sensor 30, a detection switch 32 for detecting whether the battery 12 is
held in the receptacle 14 is provided.
Inside the casing 11, as shown in FIG. 3, an arm member 20 is provided. The
arm member 20 has substantially an L-shaped cross section, and pivoted by
a shaft 22 at the bent portion of the L-shape such that the arm member 20
is rockable about the shaft 22. The charging electrodes 24a and 24b are
mounted on a hand 20a as shown if FIG. 3. On the other hand 20b of the arm
member 20, an end of a tension spring 26 is hooked, the other end of the
tension spring 26 is fixed on a chassis or the like of the charging
device. Due to the biasing force of the tension spring 26, the arm member
20 is biased in the direction indicated by arrow B. Accordingly, the
charging electrodes 24a and 24b are biased in the direction where they are
protruded from the bottom surface 14b of the receptacle 14 by the biasing
force of the spring 26. Further, the hand 20b of the arm member 20 is
connected with an actuator 28. The actuator 28 is capable of moving the
arm member 20 in a counterclockwise direction against the biasing force of
the tension spring 26. Therefore, when the actuator 28 is not driven, the
arm member 20 is located at the position as shown in FIG. 3, and when the
actuator 28 is driven, the arm member 20 rotates counterclockwise such
that the charging electrodes 24a and 24b are retracted from the bottom
surface 14b of the battery receptacle 14. In the embodiment, as the
actuator 28, a solenoid is used. As shown in FIG. 3, the solenoid 28 is
provided with a coil 28b and a movable iron core 28a which is pulled
towards the coil 28b when the coil 28b is energized. An end of the iron
core 28a is connected to a tip of the hand 20b of the arm member 20.
Therefore, when the coil 28b is energized, the iron core 28a is pulled
towards the coil 28b (in rightward direction in FIG. 3), and therefore the
arm member 20 rotates counterclockwisely about the shaft 22.
FIG. 4 is a cross sectional view similar to FIG. 3 except that the battery
12 is mounted on the charging device 10. As described before, when the
battery 12 is mounted, the pins 18a and 18a' engage with the stepped
portions 12a and 12a' of the battery 12 to stably support the battery in
the battery receptacle 14. The charging electrodes 24a and 24b are pushed
by the electrodes 13a and 13b provided on the bottom surface of the
battery 12 as shown in FIG. 3. In this condition, the arm member 20 is
rotated counterclockwisely with respect to the position shown in FIG. 3
against the biasing force of the spring 26. Since the actuator 28 is not
driven, the arm member 20 is still biased in the direction of arrow B, the
charging electrodes 24a and 24b are press-contacted to the battery
electrodes 13a and 13b, respectively. If the current source 16 starts
supplying the electrical current under control of the control unit 17, the
current is supplied to the battery through the charging electrodes 24a and
24b, and the battery electrodes 13a and 13b.
FIG. 5 is a cross sectional view of the battery 12 and the charging device
10 when the charging of the battery 12 was completed and the charging
electrodes 24a and 24b has been retracted from the bottom surface 14b of
the receptacle 14. As described before, when the charging of the battery
is completed, the actuator 28 is driven. Then, the arm member 20 is
rotated in the direction indicated by arrow C (counterclockwisely) against
the biasing force of the spring 26. While the actuator 28 is being driven,
the status as shown in FIG. 5 is maintained, and therefore the charging
electrodes 24a and 24b are maintained not to contact the battery
electrodes 13a and 13b. Since the charging electrodes 24a and 24b do not
contact the battery electrodes 13a and 13b, above described problems,
i.e., discharging and corrosion problems are resolved.
FIG. 6 is a block diagram illustrating the controlling system of the
charging device 10.
The display panel 15, the current source unit 16, the charging electrodes
24a and 24b, the actuator 28, the temperature sensor 30, and the detection
switch 32 are connected to the control unit 17.
The current source 16 is a well-known switching current source, or a
regulate current source, and supplies the electrical current when it
receives a charge instruction signal from the control unit 17. The current
source 16 has a voltage/current detection device for detecting the charged
voltage of the battery 12 and charging current with use of a shunt
register or the like.
The control unit 17 has a microprocessor provided with a timer, A/D (analog
to digital) converter to be used for performing a controlling operation.
The control unit 17 outputs the charge instruction signal in accordance
with the charged voltage and charging current detected by the
voltage/current detection device of the current source unit 16, the
temperature of the battery 12 detected by the temperature sensor 30, and
the information representing whether the battery 12 is mounted which is
detected by the detection switch 32. Further, the control unit 17 controls
the display panel 15 to display information related to the charged
voltage, charging current and the temperature of the battery 12. In the
embodiment, the display panel 15 has a plurality of LEDs (light emitting
diodes), and the information is indicated by the combination of lit LEDs.
For example, the LEDs are controlled to turn on respectively to indicate
that the charging is being executed, and/or the charging is completed.
FIG. 7 is a flowchart illustrating the operation executed by the control
unit 17.
The flowchart shown in FIG. 7 is executed when a power switch provided next
to the display panel is turned ON. At S1, the control unit 17 determines
whether the battery 12 is mounted on the charging device 10 based on
whether the detection switch 32 is on or off. If the battery 12 is not
mounted (S1:NO), the detection at S1 is repeated. If the control unit 17
determines that the battery 12 is mounted on the charging device 10
(S1:YES), the control unit 17 starts charging of the battery 12 by sending
the charge start instruction signal to the current source unit 16 (S2).
The current source unit 16 starts charging, i.e., starts supplying current
to the battery 12 through the charging electrodes 24a, 24b, and the
battery electrodes 13a and 13b. When charging starts at S2, the control
unit 17 controls the LEDs provided on the display panel 15 to indicate the
charging condition in accordance with the charging voltage, charging
current and the temperature of the battery 12.
The control unit 17 determines whether the battery 12 is removed from the
receptacle 14 during the charging operation based on the status of the
detection switch 32 (S3). If the battery 12 is removed (S3:NO), the
control unit 17 stops charging at S4, and control returns to S1 to wait
that the battery 12 is mounted. If the battery 12 is held in the
receptacle 14 (S3:YES), the control unit 17 determines whether the battery
12 is normally charged based on whether the temperature of the battery 12
detected by the temperature sensor 30 is within a predetermined
temperature range (S5). If the control unit 17 determines that the
temperature of the battery 12 is out of the predetermined temperature
range (S5:NO), the charging should be terminated because an error
condition occurs in the battery 12 and/or the charging device 10. In such
a case, control goes to S8 to stop charging, followed by steps S9 through
S11 which will be described. If the control unit 17 determines that the
temperature of the battery 12 is within the predetermined temperature
range (S5:YES), voltage of the battery 12 is detected with use of the
shunt resistor (S6). After the charged voltage of the battery 12 is
detected, whether the charging is completed is determined based on the
charged voltage at S7. If the charging has not finished yet (S7:NO),
control returns to S3 and charging is kept by repeating procedures in
steps S3 through S7. If the control until 17 determines that charging is
finished (S7:YES), the control unit 17 sends a charge stop instruction
signal to the current source unit 16 to stop charging (S8). Then, at S9,
the control unit 17 drives the actuator 28 so that the charging electrodes
24a an 24b are disconnected from the battery electrodes 13a and 13b. Note
that in the embodiment, only while the actuator 28 is being driven, the
electrodes 24a and 24b are disconnected from the battery electrodes 13a
and 13b. At S10, the control unit 17 determines whether the battery 12 is
removed from the receptacle 14 in accordance with the output signal of the
detection switch 30. If the battery 12 is held in the receptacle 14
(S10:YES), in order to prevent contact between the charging electrodes
24a, 24b and the battery electrodes 13a and 13b, the control unit 17 keeps
driving the actuator 28 by executing S9 and S10. Therefore, even if
charging of the battery 12 is completed, when the battery 12 stays mounted
on the charging device 10 (i.e., held in the receptacle 14), the actuator
28 is kept driven. If the battery 12 is removed from the receptacle 14
after the charging has completed (S10:NO), the control unit 17 stops
driving the actuator 28 since even if the charging electrodes 24a and 24b
return the position where they protrude from the bottom surface 14b of the
receptacle 14, the charging electrodes 24a and 24b do not contact the
battery electrodes 13a and 13b any more.
As described above, according to the charging device 10 described above,
the charging electrodes do not contact the battery electrodes even if the
battery stays mounted onto the charging device after charging has been
completed. Therefore, discharging of the battery through the battery
electrodes and charging electrodes are prevented. Further, corrosion of
the electrodes due to the contact thereof can also be prevented.
In the embodiment, disconnection between the charging electrodes and the
battery electrodes are achieved with use of an L-shaped arm member 20.
Instead of using the L-shaped arm member, it is also possible to use a
plate member provided with the charging electrodes thereon, and an
elevation mechanism for moving the plate member upwardly/downwardly. In
this case, a biasing member for biasing the plate member in an upward
direction.
Alternatively, the charging electrodes may be fixed onto the bottom surface
14b of the receptacle 14, and the bottom surface 14b may be made movable
in the upward/downward directions. In this case, an compression spring may
be arranged below the plate member to bias the plate member upwardly, and
an actuator is also arranged below the bottom surface 14b such that the
bottom surface is moved downwardly by the actuator to disconnect the
battery electrodes from the charging electrodes against the biasing force
of the compression spring.
Further alternatively, instead of moving the charging electrodes, it is
possible to move the battery electrodes by moving the battery 12. For this
purpose, a compression spring may be provided between the bottom surface
of the battery and the bottom surface 14b of the receptacle such that the
compression spring biases the battery 12 to move upwardly. In such a
construction, an actuator may be provided at lock pins 18a and 18a' for
releasing the engagement between the lock pins 18a, 18a' and the
engagement stepped portions 12a and 12b. When charging of the battery 12
is completed, the actuators may be driven to release the engagement of the
lock pins 18a and 18a' with the engagement stepped portions 12a and 12b.
Then, due to the biasing force of the compression spring, the battery 12
is lift and the battery electrodes are disconnected from the charging
electrodes.
In the embodiment, the tension spring 26 is used for biasing the arm member
20. Instead of the spring 26, rubber or the like having a sufficient
resilience can be used to bias the arm member 20.
Further, in the embodiment, a solenoid is used as the actuator 28. However,
the actuator 28 is not limited to the solenoid and any member which can
rotate the arm member 20 can be used. For example, a gear mechanism
utilizing a motor and gears can be used instead of the structure described
above. If the gear mechanism is to be used instead of the actuator 28, the
biasing member may be omitted since the position of the arm member may be
completely controlled by the gear mechanism. FIGS. 8 through 9 show a
second embodiment of a charging device 10M which employs the gear
mechanism as described above.
Note that in FIGS. 8 and 10, members similar to those used in the first
embodiment have been given the same reference numerals, and the
description there of are omitted. Similar to the first embodiment, when
the battery 12 is mounted on the charging device 10M, the pins 18a and
18a' engage with the stepped portions 12a and 12a' of the battery 12 to
stably support the battery in the battery receptacle 14. In the second
embodiment, charging electrodes 124a and 124b are provided. The charging
electrodes 124a and 124b have a structure as shown in FIG. 9: each
electrode has a movable member 102; a holder 101; and a compression spring
103. The holder 101 slidably holds the movable member 102 which is biased
upwardly. When the battery 12 is mounted on the casing 11 of the charging
device 10M, the movable member 102 of each one of the charging electrodes
124a and 124b are pushed by the electrodes 13a and 13b provided on the
bottom surface of the battery 12 as shown in FIG. 8.
In the second embodiment, the charging electrodes 124a and 124b are mounted
on a mounting portion 120a of an arm member 120. The arm member 120 is
rotatably supported by a shaft 122, and has a gear portion 120b. The gear
portion 120b engages with a gear 41 which is secured to a shaft 42 of a
motor 40. The arm member 120 rotates in accordance with the engagement of
the gear portion 120b with the gear 40 as the motor 40 is driven to
rotate.
Constructed as above, when the battery 12 is mounted on the charging device
10M, the movable member 102 is retracted by a certain amount against the
biasing force of the spring 103. In this condition, the movable member 102
of each one of the charging electrodes 124a and 124b press contacts the
electrodes 13a and 13b. In this case, although the electrodes 124a and
124b are pushed by the electrodes 13a and 13b of the battery 12, the arm
member 120, on which the electrodes 124a and 124b are mounted, does not
move since only the movable member 102 of each electrodes 124a (124b) is
retracted.
After the charging is completed, the motor 40 is driven such that the arm
member 120 rotates in the counterclockwise direction indicated by arrow C.
Then, the charging electrodes 124a and 124b are disconnected from the
battery electrodes 13a and 13b, respectively. Since the charging
electrodes 124a and 124b do not contact the battery electrodes 13a and 13b
after the charging is finished, the problems, i.e., discharging and
corrosion problems described before are resolved. In the second
embodiment, after the charging is completed, the arm member 120 is
positioned as shown in FIG. 10. Accordingly, when charging of another
battery is executed, the motor 40 is controlled such that the arm member
120 moves clockwisely and to be positioned as shown in FIG. 8.
According to the embodiments, firstly whether the charging of the battery
is completed is determined. Then, if the charging is finished, the
charging electrodes and the battery electrodes are disconnected.
Therefore, the battery is not discharged through the electrodes, and the
corrosion of the electrodes can also be prevented.
The present disclosure relates to subject matter contained in Japanese
Patent Application No. HEI 7-224963, filed on Sep. 1, 1995, which is
expressly incorporated herein by reference in its entirety.
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